<?php
/**
 * Created by PhpStorm.
 * User: User
 * Date: 2017/10/30
 * Time: 18:34
 */
class person{}
class student extends person{}
//is_a判断对象是否由一个类或者个类的子类实例化来的
//一参数：要判断的对象，二参数：要判断的类名　返回值　ｂｏｏｌ
$person=new person();
$student=new student();
var_dump(is_a($person,"person"));
var_dump(is_a($student,"person"));
var_dump(is_a($person,"student"));
var_dump(is_a($student,"student"));